The Curious Case of P3tra Kvitova

World No. 10 Petra Kvitova has been playing a large number of three-setters this year. Her first round win at the US Open over Misaki Doi marked her 30th three-setter of 2013 out of 60 matches played, which means she has gone to a decider in half her matches.

It’s commonly believed that the best-case scenario for any match is to win in straight sets to conserve energy, particularly if it’s against a lower-ranked opponent, so by that measure, Kvitova’s three-set record can be viewed as a negative. Setting aside the reasons and theories on why Kvitova has had so many matches go the distance, let’s dig deeper into the numbers.

Historical Context

How does Kvitova’s percentage of three-set matches played match up against her peers? I pulled numbers for the (year-end) top 10 players for the last 10 years to see how she stacks up. Here’s what I learned:

    • Top 10 players in the last 10 years averaged at 26% of their matches going to a deciding set, winning 66.4% of those matches. As we know, Kvitova has played 50% of her 2013 matches so far in three sets, winning 63.3% of those matches.
    • No top 10 player in the last 10 years ended the year at or above 50% three-setters (Kvitova’s current number).
    • Even playing more than 40% of matches in three sets by the end of the year is uncommon; the only top 10 players to do it in the last 10 years were Svetlana Kuznetsova in 2009 (42.4%), Venus Williams in 2009 (42.6%), Ana Ivanovic in 2008 (42.1%), Patty Schnyder in 2005 (43.4%), and Elena Dementieva in 2005 (40.3%).
Player Year % Three-Set Matches Played # of Matches
Petra Kvitova 2013 (inc.) 50 60
Patty Schnyder 2005 43.4 83
Venus Williams 2009 42.6 54
Svetlana Kuznetsova 2009 42.4 59
Ana Ivanovic 2008 42.1 57
Sloane Stephens 2013 (inc.) 40.8 49
Elena Dementieva 2005 40.3 67

As for hitting the mark of 30 three-setters in one calendar year, out of this group only Jelena Jankovic (2007, 31) and Patty Schnyder (2005, 36) have done it in the last 10 years.

Does It Matter?

Is this just a fluke for Kvitova, or is it something to be concerned with in the future? It’s hard to draw conclusions, but just for curiosity’s sake, let’s take a look at the other players who hit the 40% mark and whether they rebounded the following year:

  • Kuznetsova – 42.4% in 2009, 43.4 in 2010 ↑
  • Venus Williams: 42.6% in 2009, 17.8% in 2010 ↓
  • Ivanovic – 42.1% in 2008, 34.2% in 2009 ↓
  • Schnyder – 43.4% in 2005, 26.1% in 2006 ↓
  • Dementieva – 40.3% in 2005, 30.9% in 2006 ↓

So, four out of these five women reduced their percentage of three-set matches in the following year.

Additionally, Kvitova’s career percentage of three-set matches played is 31.1%, which is within a normal range.

Keeping in mind that we are dealing with less than a season’s worth of numbers for Kvitova, and thus a small sample size, my guess (for whatever that’s worth) is that this is simply an interesting anomaly, and her numbers will regress to the mean in the future.

Amy can be spotted on a tennis court in the Philadelphia area, shanking backhand volleys.

3 Responses

  1. Master Ace
    Master Ace August 30, 2013 at 11:56 am |

    Very interesting numbers on three set matches where Kvitova may set a record. Hopefully, that percentage will drop when the tour start the Asian portion of the tour.

  2. Lopsided Four-Setters, Orderly Doubles, and Sock’s Luck | Heavy Topspin: A Tennis Blog

    […] You may have noticed the string of three-set matches contested by Petra Kvitova, earning her the moniker “P3tra.”  Amy Fetherolf takes a closer look at The Changeover, finding that Kvitova’s season is every bit as unusual as it seems. […]

  3. Bluedylan
    Bluedylan August 30, 2013 at 9:31 pm |

    Interesting piece Amy, as with almost all of the stuff you write.

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